Deprecated features

[Nicolas Baradakis]

If you read the recent CVS reports, Alan and I have done some cleaning
in the source. Here is little summary:

> * post_proxy_authorize

Option deleted.

> * authorize in rlm_attr_filter

Function removed.

> * usercollide

Option removed by Alan.

> * bind_address and port

Removed from documentation, and print a warning if people still use them.

* {lower,nospace}_{user,pass}

Options deleted by Alan.

* Exec-Program and Exec-Program-Wait

Attributes deleted.

* Callback-Id special case

Obscure code deleted.

-- 
Nicolas Baradakis